Yeah, Ecuador requires Yellow Fever to enter the country; you might look into getting a Tetanus booster, Hep A and Hep B, and some malaria pills, if you want to be on the safe side. Mosquitos are a bitch; the malaria strand indigenous to that region is immune to chloraquin, (the weekly pill), so Malarone or something similar is required, but costly, as you have to take it daily prior, during and after your time there.

Thanks for the response Erin. I've gotten conflicting accounts and my understanding was no vaccination was required to enter the country.
I booked this trip last mnute and won't get any shots 4 weeks in advance.
I just spoke with a friend who travelled in Nicaragua, Bolivia and Peru without any shots. There's always the better safe spin but if people visit there without the shots I'd be interested.